The concentration and composition of the carbohydrate-containing macromolecules of gray and white matter from 8 to 85 year-old human brains will be determined. These substances include the heteropolysaccharide chains of glycoproteins, the glycosaminoglycans, and the gangliosides. The object is to ascertain whether qualitative or quantitative changes occur in these substances as a consequence of aging, and to accumulate sufficient materials in order to determine the structure of the heteropolysaccharide chains derived from glycoproteins. Human brains from 31 neurologically normal human patients are extracted with chloroform-methanol or tetrahydrofuran to recover the gangliosides. The defatted residue is treated with papain to solubilize glycopeptides and glycosaminoglycans. Glycosaminoglycans are precipitated with cetylpyridinium chloride and fractionated by CPC-cellulose column chromatography and anion exchange chromatography and analyzed to distinguish between chondroitin 4- and 6-sulfate, heparan sulfate, dermatan sulfate, hyaluronic acid, and chondroitin. Glycopeptides that act as receptors for concanavalin A are separated by means of affinity chromatography (Con A-Sepharose); this fraction will be subdivided to yield neutral and basic mannose-rich glycopeptides as well as an acidic phosphorylated mannose-rich glycopeptide. The sialoglycopeptides, which do not bind to Con A, are separated by gel filtration into three fractions which differ in molecular size (app. MW equals 4-5,000, 3,000, 2,000). The sialoglycopeptides of MW 4-5000 are treated with mild alkali to recover the alkali-labile oligosaccharides consisting of galactosamine, galactose and/or N-acetylneuraminic acid. The alkali stable glycopeptides are fractionated by chromatography on DEAE-Sephadex. Fractions eluted from the anion exchanger are treated with neuraminidase and separated into sulfated and nonsulfated forms by anion exchange chromatography (Dowex 1). The two additional minor glycopeptides of lower molecular size will also be analyzed.